#import <CommonCrypto/CommonDigest.h>

@implementation NSString (NSString_Hashing)

- (NSString *)MD5Hash
{
	const char *cStr = [self UTF8String];
	unsigned char result[16];
	CC_MD5(cStr, (uint32_t)strlen(cStr), result);
	return [NSString stringWithFormat:
			@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
			result[0], result[1], result[2], result[3],
			result[4], result[5], result[6], result[7],
			result[8], result[9], result[10], result[11],
			result[12], result[13], result[14], result[15]];
}

+ (NSString*)dataMD5:(NSData*)data
{
    CC_MD5_CTX md5;
    
    CC_MD5_Init(&md5);
    
    CC_MD5_Update(&md5, [data bytes], (uint32_t)[data length]);
    
    unsigned char digest[CC_MD5_DIGEST_LENGTH];
    CC_MD5_Final(digest, &md5);
    NSString* s = [NSString stringWithFormat: @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
                   digest[0], digest[1],
                   digest[2], digest[3],
                   digest[4], digest[5],
                   digest[6], digest[7],
                   digest[8], digest[9],
                   digest[10], digest[11],
                   digest[12], digest[13],
                   digest[14], digest[15]];
    return s;
}

+ (NSString*)fileMD5:(NSString*)path
{
    NSFileHandle *handle = [NSFileHandle fileHandleForReadingAtPath:path];
    if( handle== nil ) return @"ERROR GETTING FILE MD5"; // file didnt exist
    
    CC_MD5_CTX md5;
    
    CC_MD5_Init(&md5);
    
    BOOL done = NO;
    while(!done)
    {
        NSData* fileData = [handle readDataOfLength: 10240];
        CC_MD5_Update(&md5, [fileData bytes], (uint32_t)[fileData length]);
        if( [fileData length] == 0 ) done = YES;
    }
    unsigned char digest[CC_MD5_DIGEST_LENGTH];
    CC_MD5_Final(digest, &md5);
    NSString* s = [NSString stringWithFormat: @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
                   digest[0], digest[1],
                   digest[2], digest[3],
                   digest[4], digest[5],
                   digest[6], digest[7],
                   digest[8], digest[9],
                   digest[10], digest[11],
                   digest[12], digest[13],
                   digest[14], digest[15]];
    return s;
}

@end
